As a conventional technology, a multiprocessor system formed of plural processors has been well-known (for example, see Patent Document 1). The multiprocessor system disclosed in Patent Document 1 provides three or more processors each of which has a normal mode and a monitoring mode. In the normal mode, a processor performs information processing by executing a program. In the monitoring mode, another processor executes a program which is the same program as the processor designated to perform in the normal mode executes, and the other processor compares a processing operation of its own with a processing operation of the processor designated to perform in the normal mode. When the processing operations are different from each other, the other processor generates an abnormal operation detection signal. In addition, one of the processors is designated to be operated in the normal mode, and the other processors are designated to be operated in the monitoring mode.
When one of the processors designated to be operated in the monitoring mode generates the abnormal operation detection signal, the processor designated to be operated in the normal mode is separated from the multiprocessor system, and one of the processors designated to be operated in the monitoring mode is designated to be operated in the normal mode and the remaining processors designated to be operated in the monitoring mode are determined as they are; with this, the multiprocessor system is restructured. On the other hand, when one of the processors designated to be operated in the monitoring mode generates the abnormal operation detection signal, the processor which generates the abnormal operation detection signal is separated from the multiprocessor system, the remaining processors are designated to be operated in the monitoring mode as they are, and the multiprocessor system is rebooted.
[Patent document 1] Japanese Patent Publication to Laid-Open to Public for Opposition No. H6-30069
However, in the above conventional technology, the processor designated to be operated in the normal mode and the processors designated to be operated in the monitoring mode must execute the same program. On the other hand, in another multiprocessor system in which control to be performed is allocated to each of the processors, the same program is not always executed in the processors. Since the same program is not executed in the processors, when the conventional technology is applied to the multiprocessor system, the conventional technology cannot handle an abnormal operation being generated in a processor. In addition, in the conventional multiprocessor system, when a processor to which important control is allocated generates an abnormal operation, a countermeasure is required so that the processor to which the important control is allocated is not separated from the multiprocessor system.